CVE-2026-107335: CWE-409 Improper handling of highly compressed data (data amplification) in CISA Malcolm
Description
Malcolm's upload-processing pipeline (scripts/safe-extract.py) enforces entry-count, nesting-depth, and total-uncompressed-byte limits when extracting container archives (zip/tar/rar/7z via libarchive), but those limits are not applied when the uploaded file is a single-stream compressed format (.gz, .bz2, .xz, .lzma, .lz) that isn't a .tar.*-style archive. Any authenticated user permitted to upload PCAP/log files can upload a small, highly compressible file (e.g. a gzip bomb) that decompresses to an effectively unbounded size on disk, exhausting the shared Docker volume used by OpenSearch, Logstash, Arkime, and Zeek, and disrupting the platform for all users.
CVSS v3.1
Score 6.5medium
Affected software
CISA
Malcolm
pkg:github/cisagov/MalcolmRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Malcolm's upload-processing pipeline enforces limits on entry count, nesting depth, and total uncompressed bytes for container archives (zip, tar, rar, 7z) via libarchive. However, these limits are not applied to single-stream compressed formats such as .gz, .bz2, .xz, .lzma, and .lz when the file is not a tar-style archive. This allows an authenticated user to upload a small file that decompresses to an unbounded size on disk (a gzip bomb), exhausting disk space on the shared Docker volume used by OpenSearch, Logstash, Arkime, and Zeek, leading to denial of service for all users of the platform.
Potential Impact
The vulnerability can cause denial of service by exhausting disk space on the shared Docker volume, disrupting multiple integrated components (OpenSearch, Logstash, Arkime, Zeek) and affecting all users of the Malcolm platform. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
No patch or official fix is currently documented. Users should monitor vendor advisories for updates. Until a fix is available, restrict upload permissions to trusted users only and consider implementing external file size and decompression resource limits to mitigate potential denial of service.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- icscert
- Date Reserved
- 2026-10-07T18:31:15.966Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac7d8742cdf04f6562d26bd
Added to database: 10/08/2026, 17:52:52 UTC
Last enriched: 10/08/2026, 18:03:52 UTC
Last updated: 10/08/2026, 21:45:58 UTC
Views: 7
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